The extent of the damage was so severe that fire investigators don't know where the fire started, much less how it started, he said.

"The whole building, particularly one end, burned completely, we don't know where to start," he said, adding that investigators from the state Fire Marshal's Office had been called to the scene.

One firefighter, who Raymond did not identify, was taken to Concord Hospital suffering from a mild case of heat exhaustion. The injured firefighter returned to the scene to observe later in the morning, he said. "He's fine," Raymond said.

Locke and his family were on vacation overseas and the home was not occupied at the time of the fire, Raymond said. They were expected to return home late Monday or Tuesday, and they have been put in contact with the Red Cross for shelter, he said.

The fire was under control within an hour, and firefighters were on the scene until about 9:30 a.m., he said.

Fire departments from Webster, Contocook, Salisbury, Boscawen, Henniker, Bow, Sutton, and Bradford joined town firefighters in battling the blaze.